Method and apparatus for separating out admixtures from molten metal baths



Nov. 17, 1942. Q HANNEN METHOD AND APPARATUS FOR SEPARATING OUT ADMIXTURES FROM MOLTEN METAL BATHS Filed Jan 25 1940 Jarenfar: 028718713 Han-11c?! y 2 3% a I attorneys Patented Nov. 17, 1942 METHOD AND arrm'rus son ssrsaa'rme our anmx'ruars mom MOLTEN METAL BATES Clemens Hannen, Sinzig-on-tlie-Bhine,

Ger-

many; vested in the Alien Property Custodianv Application January 25, 1940, Serial No. 315,615 In Germany February 11, 1939 8 Claims.

It is known that undesired admixtures, especially sulphur, can be partly removed from liquid pig iron by submitting it to shaking during transport in a crucible from the blast furnace to the steel works. With this object in view a shaking, pushing or swinging movement has been imparted to the container with the liquid iron. Turning movements have also been proposed of a contalner, the lining of which is provided with ribs or the like adapted to exert thrust upon the liquid mass.

These known shaking methods have not .fulfilled the object in practical service for the reason that agitation exerted upon the container walls acted chiefly upon the sensitive, refractory linings of the containers. To penetrate to the bath itself, the shaking had to be considerably increased, which usually resulted in damage to the lining and the container itself.

Another proposal consisted in causing the liquid metal from the melting or blast furnace to flow through a stepped channel, so that by repeated dropping from step to step the desired shaking was produced. This method is unsuccessful for the reason that the liquid metal is strongly cooled while flowing through the channel and is rendered unsuited for subsequent treatment.

Also attempts to propagate ultra-sound waves into the metal bath or liquid iron mass, were not successful, as these waves exerted an efiect only if they were introduced into the liquid mass by means of plunging rods or the like, this again favouring cooling. Also, it was found to be impossible to increase the shaking by ultra sound waves beyond a measure at which mere separation of gas from the metal bath took place.

The shaking method according to the present invention obviates these inconveniences. It consists therein, that mechanical shaking is transmitted directly to the liquid metal mass only-on the surface of the bath. Practically the shaking is produced by exerting sharp mechanical shocks or beats upon a plate placed on the surface of the bath.

As the plate rests on the surface of the bath, that is does not dip into thebath, it can be protected against burning and melting by coverin the bath with suitable granular. powdery or liquid substances, these protecting media serving at the sametime as binding agent for the separated admixtures, and to protect the bath against cooling.

A container filled with liquid metal and serving for transport is diagrammatically illustrated in section in the only figure of the accompanying shown in section acting upon the surface of the bath.

A plate 0 is lowered on to the surface of the metal bath b in the container 1:. This plate c is of such shape, that it either floats freely on the bath, or it is spring suspended as shown in the drawing.

To produce the shaking, beats are exerted in rapid succession upon plate c by a beating device e which is shown on the drawing by way of example as a piston moved to and fro by suitable means, for instance mechanical, pneumatic, hydraulic, or electrical, these beats acting directly upon the bath b without exerting any prejudicial effect upon the container a and the lining of the same. 7

The surface d of the bath is prefer-ably covered with suitable granular, powdered or liquid substances, such as quick-lime, soda, charcoal, ashes from coke, slag or the like or mixtures ofthe same, before plate 0 is placed on the bath. This covering serves, if necessary, to bind or to render harmless the separations, and further to protect the plate from the liquid metal, and it has also the effect of avoiding cooling of the bath.

I claim:

1. A method for the separation of admixtures from baths of liquid molten metal in a vessel, consisting in introducing mechanical shaking to the surface only of the molten metal in the bath.

2. A method according to claim 1, in which the shaking is produced by imposing sharp mechanical shocks or beats upon a plate resting on the surface of the bath.

3. A method according to claim 1, in which the shaking is produced by imposing sharp mechanical shocksor beats upon a plate resting on the surface of the bath, and in which the plate is protected against burning and melting by covering the bath with a protecting medium.

4. A method for the separation of admixtures from baths of liquid molten metal in a transport vessel, consisting in introducing mechanical agitation to the surface only of the molten metal by means resting on said surface without penetration into the metal, and protecting said means by a medium acting as a binding agent for the admixture to be separated and covering said means and the surface of the molten metal.

5. A method according to claim 4 in which the surface of the molten metal and the agitating means are kept covered with a protecting medium in granular form.

6. Apparatus for separating admixtures from drawing, a mechanical shaking device partly molten metal in lined transport vessels comprisfor maintaining said lower plate face in contact 2 2301,94? ing aplate member with its lower face adapted with said molten metal surface.-and means including a piston acting directly on the plate member for imparting shocks to said plate.

8. Apparatus for separating admixtures from molten metal in lined vessels comprising a plate member with its lower face adapted to contact and float on a substantial area of the surface of the molten metal in the vessel, and means including a piston acting directly on the plate 10 member for imparting shocks to said plate.

CLEMENS HANNEN. 

